Molecular combing compared to Southern blot for measuring D4Z4 contractions in FSHD.

We compare molecular combing to Southern blot in the analysis of the facioscapulohumeral muscular dystrophy type 1 locus (FSHD1) on chromosome 4q35-qter (chr 4q) in genomic DNA specimens sent to a clinical laboratory for FSHD testing. A de-identified set of 87 genomic DNA specimens determined by Southern blot as normal (n = 71), abnormal with D4Z4 macrosatellite repeat array contractions (n = 7), indeterminate (n = 6), borderline (n = 2), or mosaic (n = 1) was independently re-analyzed by molecular combing in a blinded fashion. The molecular combing results were identical to the Southern blot results in 75 (86%) of cases.

Spectral Karyotyping for identification of constitutional chromosomal abnormalities at a national reference laboratory.

Spectral karyotyping is a diagnostic tool that allows visualization of chromosomes in different colors using the FISH technology and a spectral imaging system. To assess the value of spectral karyotyping analysis for identifying constitutional supernumerary marker chromosomes or derivative chromosomes at a national reference laboratory, we reviewed the results of 179 consecutive clinical samples (31 prenatal and 148 postnatal) submitted for spectral karyotyping. Over 90% of the cases were requested to identify either small supernumerary marker chromosomes (sSMCs) or chromosomal exchange material detected by G-banded chromosome analysis.

Fluorescence in situ hybridization and K-ras analyses improve diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration of solid pancreatic masses.

Objectives: Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is the main diagnostic modality for pancreatic mass lesions. However, cytology is often indeterminate, leading to repeat FNAs and delay in care. Here, we evaluate whether combining routine cytology with fluorescence in situ hybridization (FISH) and K-ras/p53 analyses improves diagnostic yield of pancreatic EUS-FNA.